School administrators called sheriff's deputies after receiving information that a 13-year-old student threatened to bring an AR-15 rifle to school. Witnesses told administrators the teenager said he was going to bring the gun to school on Wednesday.

Students said they were scared because "they'd seen a picture of that same boy holding an AR-15 on Snapchat about a month ago," said Ashley Ritchie, spokeswoman for the sheriff.

Students submitted an anonymous tip using the school's online bully reporting system.

The student's mother is cooperating with law enforcement and school officials, Ritchie said. Deputies were allowed to search the student's home. No weapons were found.

It's unclear whose rifle the boy was holding in the Snapchat video. Police could use the video to seek criminal charges.

The student was arrested and booked into Tulare County Juvenile Detention Facility on suspicion of making criminal threats.

"Sheriff (Mike Boudreaux) wants to remind everyone that threats like this are never a joke and will always be taken very seriously by the Tulare County Sheriff's Department," Ritchie said.

Anyone with information is encouraged to call the sheriff's department at 733-6218 or (800) 808-0488.

On Monday, a Redwood High School student was arrested after police said he confessed to writing a threatening message on a bathroom stall wall.

It was the second threat at the high school in as many weeks.

The message stated: “If school isn’t evacuated tomorrow I will bring a gun and kill as many people as possible."